Fulvia alternator issue

[RobD]

The generator lamp is showing red when the car is running suggesting something is amiss with alternator. The battery is fresh and in good nick. At tickover the alternator is putting out a healthy 14.2 volts [measured at the battery terminals] However , when I increase the tickover to 1500prm or above the voltage fluctuates wildly between 10 and 16.4 volts which suggests the voltage regulation on the alternator is faulty. Has anybody any experience of this? Is there a straightforward fix or am I looking at a replacement alternator?
Bob

[lancianut666]

fan belt slipping?

[RobD]

First thing I checked...

[lancialulu]

Is it a ducillier or Bosch alternator? If a D alt check the connections on the remote regultor. You can open these up and check the contacts of the regulator. Alternatively you may have a diode gone in the alternator. A good auto electrical shop should be able to check the alternator (albeit they will never have seen one) and overhaul as neccessary. But first you could strip it and check the brushes as they may have worn to limit. Easy to strip and easy to match the brush at an auto electrician.

[Richard Fridd]

I had a problem once, where the alternator would not charge over 4000rpm. Not useful at the hillclimb I was competing in.  Different diodes for different rev ranges. I do have a surplus Fulvia alternator for sale in my spares ad.

[RobD]

Richard, I've sent you an email re the alternator, could be that I might need it in the near future!
Regards, bob

[Richard Fridd]

No email received at present, but the used condition alternator is £60, if of interest. To put the cost into context, I have recently had my boat alternator repaired at a cost of £140.